The present invention relates to a cushioning conversion machine and method in which the cross-sectional geometry of a pad may be selectively varied.
In the process of shipping an item from one location to another, a protective packaging material is typically placed in the shipping case, or box, to fill any voids and/or to cushion the item during the shipping process. Some conventional commonly used protective packaging materials are plastic foam peanuts and plastic bubble pack. While these conventional plastic materials seem to adequately perform as cushioning products, they are not without disadvantages. Perhaps the most serious drawback of plastic bubble wrap and/or plastic foam peanuts is their effect on our environment. Quite simply, these plastic packaging materials are not biodegradable and thus they cannot avoid further multiplying our planet""s already critical waste disposal problems. The non-biodegradability of these packaging materials has become increasingly important in light of many industries adopting more progressive policies in terms of environmental responsibility.
These and other disadvantages of conventional plastic packaging materials has made paper protective packaging material a very popular alterative. Paper is biodegradable, recyclable and renewable; making it an environmentally responsible choice for conscientious industries. While paper in sheet form could possibly be used as a protective packaging material, it is usually preferable to convert the sheets of paper into a relatively low density pad-like cushioning dunnage product. This conversion may be accomplished by a cushioning conversion machine, such as that disclosed in U.S. Pat. No. 5,322,477. (This patent is assigned to the assignee of the present application and its entire disclosure is hereby incorporated herein by reference.)
In a cushioning conversion machine which forms sheet-like stock material into a continuous strip, the cross-sectional geometry (i.e., the width) of the strip essentially dictates the cross-sectional geometry (i.e., the width) of the resulting cushioning product. For example, in the cushioning conversion machine disclosed in U.S. Pat. No. 5,322,477, the cross-sectional geometry of the cushioning product, and specifically its width, is determined by the machine""s forming assembly, and more particularly a chute, and even more particularly, the exit end of the chute.
In the commercial embodiments of the cushioning conversion machine disclosed in U.S. Pat. No. 5,322,477, the cushioning product is about 8 to 10 inches in width. This pad size is acceptable and suitable, and even preferred, for many packaging applications. However, occasionally, a slightly smaller width pad (i.e., 7xc2xd inches) is required to accommodate certain packaging applications. Additionally, especially in sophisticated packaging systems, pads of differing widths may be required, or at least desired, to package articles of differing dimensions and shapes.
U.S. Pat. Nos. 4,884,999; 5,061,543 and 5,188,581 disclose a cushioning conversion machine/method for making a cushioning product having a width of about 3xc2xd to 4 inches. The disclosed machine/method is the result of a revamping of a xe2x80x9cstandardxe2x80x9d cushioning conversion machine into a machine capable of producing the relatively narrow cushioning product from fifteen-inches wide (as opposed to the thirty-inch wide) stock material. This revamping is accomplished by a kit which includes a funnel member, substantially smaller in cross-sectional dimensions than the converging chute, and an elongated bar-like member. To revamp the machine, the forming frame would be removed, as it is not used to produce the narrow width cushioning product. The converging chute would likewise not be used during the narrow width pad production, but it could either be left on the machine or removed. The components of the kit (the narrow funnel member and the bar-like member) are then installed on the machine, and once installed, the revamped machine can be used to produce narrow width pads. If it is desired to return to the original sized pads, the kit components are removed and replaced with the original components to return the machine to full size production.
Thus, in the past, to the extent that the cross-sectional geometry of a cushioning pad has been changed, this change was accomplished by the replacement of forming assembly components. Thus, if a different width pad (i.e., 7xc2xd inches, 7 inches, 6xc2xd inches, 6 inches, 5xc2xd inches, etc.) is required, an alternate forming assembly would have to be supplied, for each desired pad width. Needless to say, the complications of such a system would place a strain on machine manufacture. Also, continuous revamping of machines to provide different width pads would not be able to accommodate sophisticated packaging systems which require pads of differing widths to package articles of differing dimensions and shapes.
The present invention provides a cushioning conversion machine including a device for selectively adjusting the cross-sectional geometry of a cushioning pad produced by a cushioning conversion machine. This adjustment may be accomplished without the replacement of forming assembly components and allows a large range of adjustments. Additionally or alternatively, the cushioning conversion machine is able to accommodate sophisticated packaging systems which require pads of differing widths to package articles of differing dimensions and shapes.
In the preferred form of the invention, the cushioning conversion machine comprises a forming assembly which forms sheet-like stock material into a strip; a feed assembly which advances the stock material through the forming assembly; and a device which controls the width of the strip and which may be selectively adjusted to change the width of the strip.
The preferred device includes a pair of guide members and a mounting assembly mounting the guide members relative to the machine""s frame. The preferred forming assembly includes a chute and the preferred feed assembly includes a pair of rotating feed members. The mounting assembly positions the guide members between the output of the chute and the rotating feed members and allows selective adjustment of the spacing between the guide members.
The mounting assembly preferably allows selective adjustment of the guide member spacing between a distance which is the same or greater than the width of the exit end of the chute and a distance which is less than the width of the exit end of the chute. More preferably, the mounting assembly allows selective adjustment of the guide member spacing to a plurality of distances which are less than the width of the exit end of the chute.
In certain preferred embodiments of the invention, the guide members are rollers which are rotatably mounted on the mounting assembly whereby they may freely turn as the strip passes therethrough. The rollers have a concave shape and more specifically have a spool shape with an axial dimension approximately equal to the height of the exit end of the chute and positioned to surround the lateral edges of the strip as it emerges from the chute. In another preferred embodiment, the mounting assembly is fixed relative to the machine""s frame and the guide members are selectively positionable on (although non-rotatably supported by) the fixed mounting assembly.
In certain preferred forms of the invention, the pad-adjustment device includes at least one adjustment member which is moved among a plurality of positions to change the width of the strip and the device includes a motorized drive, such as a reversible rotary motor, which moves the adjustment member among the plurality of positions. The cushioning conversion machine may additionally comprise a control system for controlling the motorized drive to move the adjustment member among the plurality of positions.
In a preferred method of converting sheet-like stock material into a three-dimensional cushioning product according to the present invention, the sheet-like stock material is supplied to the cushioning conversion machine. The stock material is converted into a strip of a certain width, the pad-adjustment device is adjusted, and the stock material is converted into a strip of different width. Such a method will produce a cushioning product according to the present invention which has continuous portions of different widths. The converting and adjusting steps may be performed sequentially and in such a manner that the cushioning product according to the present invention has discrete sections of different widths. Alternatively, the converting and adjusting steps may be performed substantially simultaneously and in such a manner that the cushioning product according to the present invention has a gradually tapering shape.
In another preferred method of converting sheet-like stock material into a three-dimensional cushioning product according to the present invention, sheet-like stock material is formed into a first strip of a certain width by inwardly turning the lateral edges of the sheet-like stock material and then the first strip is formed into another strip of a less width by inwardly turning the outer lateral sides of the first strip. The second forming step may be accomplished by a pad-adjustment device according to the present invention. In any event, a cushioning product is produced which comprises two lateral pillow-like portions, each including inwardly turned lateral edges of the sheet-like stock material which have once again been inwardly turned.